Systems and methods for transport climate control circuit management and isolation

ABSTRACT

A method of controlling a transport climate control system includes detecting for leaking of working fluid from a climate control circuit. The method also includes isolating a high-pressure side of the climate control circuit when leaking of the working fluid is detected. A method of controlling a transport climate control circuit includes detecting for overcharge and/or an undercharge of the climate control circuit. A transport climate control system includes a climate control circuit and a climate controller that is configured to detect for working fluid leaking from the climate control circuit. The climate controller configured to isolate a high-pressure side of the climate control circuit when leaking of the working fluid is detected.

FIELD

This disclosure generally relates to transport climate control systems.More specifically, this disclosure relates to detecting and minimizingleakage from a climate control circuit of a transport climate controlsystem and/or mitigating overcharge or undercharge of the climatecontrol circuit.

BACKGROUND

A transport climate control system is generally used to controlenvironmental condition(s) (e.g., temperature, humidity, air quality,and the like) within a climate controlled space of a transport unit(e.g., a truck, trailer, a container (such as a container on a flat car,an intermodal container, etc.), a box car, a semi-tractor, a bus, orother similar transport unit). The transport climate control system caninclude, for example, a transport refrigeration system (TRS) and/or aheating, ventilation and air conditioning (HVAC) system. The TRS cancontrol environmental condition(s) within the climate controlled spaceto maintain cargo (e.g., produce, frozen foods, pharmaceuticals, etc.).The HVAC system can control environmental conditions(s) within theclimate controlled space to provide passenger comfort for passengerstravelling in the transport unit. In some transport units, the transportclimate control system can be installed externally (e.g., on a rooftopof the transport unit, under the transport unit, on a front wall of thetransport unit, etc.).

The transport climate control system can include a climate controlcircuit with a compressor, a condenser, an expansion valve, and anevaporator. A working fluid can include a refrigerant that can becompressed and expanded as it flows through the climate control circuitand can be used to heat and/or cool the particular space.

SUMMARY

The embodiments described herein are generally directed to detecting andminimizing leakage from a climate control circuit in a transport climatecontrol system (“TCCS”) and/or mitigating overcharge or undercharge ofthe climate control circuit.

Transport units can have a climate controlled space for cargo orpassengers that is provided climate control (e.g., heated, cooled, etc.)by a climate control circuit of a transport climate control system. Theclimate control circuit can utilize a working fluid. The working fluidcan include a flammable refrigerant. In some instances, the flammablerefrigerant can leak from the climate control circuit into the climatecontrolled space. The climate control circuit can contain an amount ofrefrigerant that is sufficient to make the climate controlled spaceflammable. Minimization of the amount of leakage from the climatecontrolled circuit may be desirable to prevent the climate controlledspace from becoming a flammable environment.

Disclosed embodiments are capable of operating a TCCS to minimizepotential leakage of the working fluid into a climate controlled space.Disclosed embodiments can isolate a high-pressure side of the climatecontrol circuit to mitigate the potential of working fluid leaking intothe climate controlled space. The disclosed embodiments can, forexample, close an electronic expansion and isolation valve (EEIV) andshutdown a compressor to isolate the high-pressure side. Some disclosedembodiments can detect an overcharge or undercharge of the climatecontrolled circuit based on the performance of the EEIV.

In an embodiment, a method is directed to controlling a TCCS for atransport unit. The TCCS includes a climate control circuit with acompressor and an electronic expansion and isolation valve (EEIV). Themethod includes operating the climate control circuit to condition aclimate controlled space of the transport unit. Operating the climatecontrol circuit to condition the climate controlled space includescompressing a working fluid with the compressor and expanding theworking fluid with the EEIV. The method also includes detecting forleaking of the working fluid from the climate control circuit andisolating the high-pressure side of the climate control circuit whendetected that the working fluid is leaking from the climate controlcircuit.

In an embodiment, the method also includes isolating a portion of thelow-pressure side of the climate control circuit when the leaking of theworking fluid is detected. In an embodiment, the climate control circuitincludes an evaporator that heats the working fluid. The portion of thelow-pressure side extends through an evaporator unit that contains theevaporator.

In an embodiment, the climate control circuit includes an isolationvalve that is downstream of the evaporator and upstream of thecompressor in the climate control circuit. The portion of thelow-pressure side of the climate controlled circuit is isolated by atleast closing an isolation valve.

In an embodiment, the isolating of the high-pressure side of the climatecontrol circuit isolates the high-pressure side from the low-pressureside of the climate control circuit.

In an embodiment, isolating the high-pressure side of the climatecontrol circuit includes closing the EEIV and shutting down thecompressor.

In an embodiment, the method includes detecting, via a step positionsensor, a step position of a stepper motor of the EEIV, and detecting atleast one step position of the EEIV and one or more other operationalparameters of the climate control circuit. The method also includescomparing operation of the EEIV to an expected operation of the EEIV,the expected operation of the EEIV being operation of the EEIV expectedfrom the detected at least one step position of the EEIV and thedetected one or more other operational parameters of the climate controlcircuit.

In an embodiment, the method includes determining a subcooling of thecompressed working fluid. The subcooling is determined based on adetected pressure and temperature of the compressed working fluidposition of the EEIV. The method determines that the climate controlcircuit is overcharged when the subcooling is greater than apredetermined threshold.

In an embodiment, the climate control circuit includes an electroniccheck valve that is downstream of the evaporator and upstream of thecompressor in the climate control circuit. The method includesdetermining a location of a leak in the climate control circuit based ona valve positon of an electronic check valve.

In an embodiment, a method is directed to controlling a TCCS for atransport unit. The TCCS includes a climate control circuit with acompressor to compress a working fluid and an electronic expansion andisolation valve (EEIV) to expand the working fluid. The method includesdetecting for overcharge of the climate controlled circuit.

The method includes a subcooling of the compressed working fluid. Thesubcooling is determined based on a detected pressure and temperature ofthe compressed working fluid. The method determines that the climatecontrol circuit is overcharged when the subcooling is greater than apredetermined threshold.

In an embodiment, the detected temperature of the compressed workingfluid is detected via a temperature sensor of the EEIV.

In an embodiment, a TCCS for a transport unit includes a climate controlcircuit and a climate controller. The climate control circuit includes acompressor, a condenser, an EEIV, and an evaporator for a working fluid.The compressor compresses the working fluid, the condenser cools thecompressed working fluid, the EEIV expands the cooled working fluid, andthe evaporator heats the expanded working fluid.

The climate controller detects for leaking of the working fluid from theclimate control circuit. The climate controller isolates a high-pressureside of the climate control circuit when leaking of the working fluid isdetected.

In an embodiment, the climate controller at least closes the EEIV andshuts down the compressor to isolate the high-pressure side of theclimate control circuit.

In an embodiment, the EEIV includes a stepper motor and a step positionsensor. The step position sensor is for detecting a step position of thestepper motor. The climate controller detects, via the step positionsensor, the step position of the stepper motor. The climate controllercompares operation of the EEIV to an expected operation of the EEIV todetermine whether working fluid is leaking. The expected operation ofthe EEIV being operation of the EEIV expected from at least one detectedstep position and one or more other detected operational parameters ofthe climate control circuit.

In an embodiment, the climate control circuit includes an isolationvalve downstream of the evaporator and upstream of the compressor. Whenleaking of the working fluid is detected, the climate controllerisolates a portion of a low-pressure side of the compressor by closingthe isolation valve.

In an embodiment, the climate control circuit includes an electroniccheck valve with a proximity sensor. The climate controller detects, viathe proximity sensor, a valve position of the electronic check valve.The climate controller also determines a location of a leak in theclimate control circuit based on the detected valve position of theelectronic check valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Both described and other features, aspects, and advantages of transportclimate control systems and methods of controlling a transport climatecontrol system will be better understood with the following drawings:

FIG. 1 is a prospective view of an embodiment of a climate controlledtransport unit attached to a tractor.

FIG. 2 is a schematic diagram of a climate control unit for a transportclimate controlled system, according to one embodiment.

FIG. 3 is a schematic diagram of a climate control unit for a transportclimate controlled system, according to another embodiment.

FIG. 4 is a flow chart of a method of controlling a transport climatecontrol system, according to one embodiment.

FIG. 5 is a flow chart of a method of controlling a transport climatecontrol system, according to another embodiment.

FIG. 6 is a flow chart of a method of controlling a transport climatecontrol system, according to yet another embodiment.

Like reference characters refer to similar features.

DETAILED DESCRIPTION

The embodiments described herein are generally directed to detecting andminimizing leakage from a climate control circuit in a transport climatecontrol system (“TCCS”) and/or detecting overcharging or underchargingof the climate control circuit.

In the following detailed description, reference is made to theaccompanying drawings, which illustrate embodiments in which theinvention may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice what isclaimed, and it is to be understood that other embodiments may beutilized without departing form the spirit and the scope of the claims.The following detailed description and the accompanying drawings,therefore, are not to be taken in a finite sense.

Different types of goods/cargo may need to be stored at specificenvironmental condition(s) while being stored within a transport unit.For example, perishable goods may need to be stored within a specifictemperature range to prevent spoilage and liquid goods may need to bekept at a temperature above their freezing point. Also, goods havingelectronic components may need to be kept in environmental conditionswith a lower moisture content to avoid damage to their electroniccomponents. Passengers traveling in the transport unit may need to bekept in a climate controlled space with specific environmentalcondition(s) to ensure their comfort while traveling. For example, theclimate controlled space containing the passengers should be at atemperature that is generally comfortable for passengers. A transportclimate control system may blow conditioned air into the climatecontrolled space of the transport unit to keep the air within theclimate controlled space at the desired environmental conditions.

ASHRAE Standard 34 (e.g., ASHRAE 34-2019) provides guidelines fordetermining the safety classification of a refrigerant or a refrigerantblend. Generally nonflammable refrigerants or blends are classified asClass 1, while highly flammable refrigerants or blends are classified asClass 3. Lower toxicity refrigerants or blends are classified “A”, whilehigher toxicity refrigerants or blends are classified “B”. Previously,many A1 refrigerants (e.g., R22, R134a, R410A, R125A, etc.) have beenused due to generally being safe and providing good performance.Presently, most to all of the A1 refrigerants currently being used havebeen found to have a high global warming potential (“GWP”) and thereforesignificantly contribute to global warming when leaked into theenvironment. A variety of refrigerant and refrigerant blends (e.g., R32,R1234yf, R1234ze(E), etc.) have a lower GWP while providing performance(e.g., capacity, temperature glide, operating pressures, etc.)comparable to current A1 refrigerants. However, many of these comparablerefrigerants/refrigerant blends are mildly flammable (e.g., classifiedas A2L) and therefore have been avoided due the dangerous flammableenvironment they can create when leaked into an enclosed space.

The embodiments described herein are generally directed to detecting andminimizing leakage from a climate control circuit in a TCCS, and/ordetecting overcharging or overcharging of the climate control circuit.The climate control circuit includes a compressor for compressing aworking fluid and a EEIV for expanding the working fluid. The workingfluid including a flammable refrigerant. The climate controlled circuitis configured to providing conditioning (e.g., heating, cooling, etc.)to a climate controlled space. The TCCS includes a climate controllerfor controlling the climate control circuit. For example, the climatecontroller is configured to isolate the high-pressure side of theclimate control circuit when leaking of working fluid is detected. Thiscan advantageously limit the flow of working fluid within the climatecontrol circuit such that the amount of refrigerant that can leak into aclimate controlled space is reduced/minimized.

FIG. 1 illustrates one embodiment of a climate controlled transport unit1 attached to a tractor 5. The climate controlled transport unit 1includes a transport unit 10 and a transport climate control system(“TCCS”) 20 for the transport unit 10. Dashed lines are used in FIG. 1to illustrate features that would not be visible in the view shown. Thetransport unit 10 may be attached to the tractor 5 that is configured totow the transport unit 10 to and from different locations. When notbeing transported, the transport unit 10 may be parked and unattachedfrom the tractor 5. It will be appreciated that the embodimentsdescribed herein are not limited to tractor and trailer units, but canapply to any type of transport unit such as a container (e.g., acontainer on a flat car, an intermodal container, etc.), a truck, a boxcar, a commercial passenger vehicle (e.g., school bus, railway car,subway car, etc.), or other similar transport unit.

The TCCS 20 includes a climate control unit (“CCU”) 30 that providesenvironmental control (e.g. temperature, humidity, air quality, etc.)within a climate controlled space 12 of the transport unit 10. Theclimate controlled space 12 is an internal space of the transport unit10. The CCU 30 provides conditioned air into the climate controlledspace 12 of the transport unit 10 to provide a desired conditionedenvironment for the goods being held within the climate controlled space12 of the transport unit 10. The desired conditioned environment for theclimate controlled space 12 can have one or more desired environmentalconditions (e.g., temperature, humidity, air quality, etc.). Forexample, the CCU 30 may provide cooled air to the climate controlledspace 12 when perishable goods are being kept within the transport unit10. In another example, the CCU 30 may dehumidify the air within theclimate controlled space 12 of the transport unit 10 when electronicsare within the transport unit 10. The CCU 30 includes a climate controlcircuit (e.g., see FIG. 2 , see FIG. 3 , etc.) for providing conditionedair to the climate controlled space 12.

The CCU 30 is disposed on a front wall 14 of the transport unit 10. Inother embodiments, it will be appreciated that the CCU 30 can bedisposed, for example, on a roof 14 or another wall of the transportunit 10. The climate controlled transport unit 1 can include a battery(not shown), an internal combustion engine (not shown), or a both as apower source. The TCCS 20 may be a hybrid power system that uses acombination of battery power and engine power or an electric powersystem that does not include or rely upon an internal combustion engineof the TCCS 20 or the tractor 5 for power.

The TCCS 20 also includes a programmable climate controller 40 and oneor more sensors 50. The sensor(s) 50 are configured to measure one ormore parameters of the climate controlled transport unit 1 (e.g., anambient temperature and/or ambient humidity outside of the transportunit 10, a compressor suction pressure, a compressor discharge pressure,a temperature of air supplied into the climate controlled space 12 bythe CCU 30, a temperature of air returning from the climate controlledspace 12 to the CCU 30, a humidity within the climate controlled space12, etc.) and communicate parameter data to the climate controller 40.The climate controller 40 is configured to control operation of the TCCS20 including components of the climate control circuit. The climatecontroller 40 may be a single integrated control unit 42 or a controlunit formed by a distributed network of climate controller elements 42,44. The number of distributed control elements in a given network candepend upon the particular application of the principles describedherein.

FIG. 2 is a schematic diagram of an embodiment of a CCU 100. The CCU 100can be utilized in a TCCS (e.g., the TCCS 10 in FIG. 1 , etc.) tocondition a climate controlled space 102. The CCU 100 includes a climatecontrol circuit 130 that is utilized to control environmentalcondition(s) (e.g., temperature, humidity, air quality, etc.) of theclimate controlled space 102. In an embodiment, the climate controlledspace 102 is the climate controlled space of a transport unit (e.g.,climate controlled space 12 of transport unit 10 in FIG. 1 , etc.). TheCCU 100 includes an evaporator unit 110 and a condenser unit 120.

The evaporator unit 110 includes an evaporator air inlet 112, anevaporator air outlet 114, and an internal volume 116. Air passesthrough the evaporator unit 110 by entering through the evaporator airinlet 112 and exiting through the evaporator air outlet 114. Inparticular, air from the climate controlled space 102 enters theevaporator unit 110 through the air inlet 112, the air is conditionedwithin the evaporator unit 110 (e.g., heated, cooled, etc.), and theconditioned air is discharged from the evaporator unit 110 through theevaporator air outlet 114. The conditioned air flows from the evaporatorair outlet 114 to the climate controlled space 102 and conditions theclimate controlled space 102. The evaporator air inlet 112 can also bereferred to as an air return inlet, and the evaporator air outlet 114can also be referred to as a conditioned air outlet.

The condenser unit 120 includes an ambient air inlet 122, an ambient airoutlet 124, and an internal volume 126. Ambient air from the externalenvironment 104 (e.g., ambient air from outside the climate controlledtransport unit 1 in FIG. 1 , etc.) flows through the condenser unit 120by entering through its ambient air inlet 122 and exiting through itsambient air outlet 124.

In FIG. 2 , the evaporator unit 110 includes a damper 118 that regulatesthe flow rate of the conditioned air from the evaporator unit 110. Itwill be appreciated that the evaporator unit 110 and the condenser unit120 in various embodiments may each include one or more fan(s) and/ordamper(s) to control the flow of respective air therethrough. Forexample, the evaporator unit 110 can include one or more evaporatorblowers (not shown) that discharges conditioned air through theevaporator air outlet 114 and/or retrieves air from the climatecontrolled space 104 through the evaporator air inlet 112. For example,the condenser unit 120 can include one or more condenser fans (notshown) that pushes air out of the condenser unit 120 through the ambientair outlet 124.

The internal volume 116 of the evaporator unit 110 is separate from theinternal volume 126 of the condenser unit 120. For example, the CCU 100can include a bulkhead 105 that separates the internal volume 116 of theevaporator unit 110 from the internal volume 126 of the condenser unit120. Accordingly, air and/or leaked refrigerant within the condenserunit 120 generally cannot flow into the evaporator unit 110 andtherefore cannot flow into the conditioned space climate controlledspace 102 (e.g., the internal volume 116 of the condenser unit 120 isnot fluidly connected to the climate controlled space 102).

As shown in FIG. 2 , the climate control circuit 130 includes componentsthat are located in the evaporator unit 110 and components that arelocated in the condenser unit 120, as discussed in more detail below.The climate control circuit 130 extends through the bulkhead 105. Thepipes, hoses, etc. of the climate control circuit 130 extend through thebulkhead 105 to pass the working fluid between the components of climatecontrol circuit 130 in the evaporator unit 110 and the components of thecomponent of the climate control circuit 130 in the condenser unit 120.

The climate control circuit 130 includes a compressor 132, a condenser134, an electronic expansion and isolation valve (EEIV) 140, and anevaporator 150. As shown in FIG. 2 , the climate control circuit 130 canalso include a receiver tank 152, an economizer 154, a distributor 156,and an accumulator tank 158. In an embodiment, the climate controlcircuit 130 can be modified to include additional components, such as,for example, one or more additional valve(s), sensor(s), an overflowtank, a filter drier, or the like.

Operation of the climate control circuit 130 is controlled by aprogrammable climate controller 180. The climate controller 180 isconfigured to detect various operating parameters of the climate controlcircuit 130. For example, the climate controller uses one or moresensor(s) (e.g.; sensors 50 in FIG. 1 ; proximity sensor 162, stepposition sensor 182, temperature sensor 184, temperature sensor 186,etc.) for detecting one or more operating parameters of the climatecontrol circuit 130. In an embodiment, the climate controller 180 is aclimate controller of a transport climate controller system (e.g., theclimate controller 40 of the TCCS 20 in FIG. 1 ). In an embodiment, theclimate controller 180 includes a memory (not shown) for storinginformation and a processor (not shown). The climate controller 180 isconfigured to control operation of the CCU 100 and its components. Theclimate controller 180 is shown in FIG. 2 as a single integrated controlunit. However, it will be appreciated that the climate controller 180 inan embodiment may a single integrated control unit or a distributednetwork of climate controller elements (e.g., distributed network ofclimate controller elements 42, 44 in FIG. 1 , etc.).

The components of the climate control circuit 130 are fluidly connected.Dashed lines are provided in FIGS. 2-6 to indicate optional features orlocations. Dashed dotted lines are provided in FIGS. 2 and 3 toillustrate electronic communications between different components. Forexample, a dashed dotted line extends from the climate controller 180 tothe compressor 132 as the climate controller 180 is configured tocontrol the compressor 132. Dotted arrows are provided in FIGS. 2 and 3to indicate flows of air into and out of the evaporator unit 110 and thecondenser unit 120.

A working fluid flows through climate control circuit 130. The workingfluid can include one more flammable refrigerants. In an embodiment, therefrigerant of the working fluid includes one or more refrigerants thatclassify as A2L. For example, the refrigerant can be a singlerefrigerant or a refrigerant blend (e.g., a combination of two or morerefrigerants) that classifies as A2L refrigerant. For example, theworking fluid can include one or more of, but is not limited to, R32,R1234yf, R1234ze(E), and R454C. It should be noted that a working fluidcan also include non-refrigerant components. For example,non-refrigerant components can be, but not limited to, lubricants,impurities, refrigeration system additives, tracers, ultraviolet dyes,and solubilizing agents. In general, these additional components arepresent in small concentrations relative to the refrigerant(s) in theworking fluid.

In an embodiment, the climate control circuit 130 is configured tooperate in a cooling mode to provide conditioned air (e.g., cooled air)to the ambient space 102. Flow of the working fluid through the climatecontrol circuit 130 in the cooling mode when operating normally (e.g.,working fluid is not leaking, etc.) is described below. Generally, themain flow path in the climate control circuit 130 for the working fluidis from the compressor 132 to the condenser 134, from the condenser 134to the EEIV 140, from the EEIV 140 to the evaporator 150, and from theevaporator 150 to back to the compressor 132.

Beginning at the compressor 132, the compressor 132 includes a suctionport 133A and a discharge port 133B. Working fluid in a lower pressuregaseous state or mostly gaseous state is suctioned into the compressor132 via its suction port 133A. The working fluid is compressed as itflows through the compressor 132. Compressed working fluid is dischargedfrom the compressor 132 via its discharge port 133B and flows to thecondenser 134. The lower pressure working fluid flows into the suctionport 133A of the compressor 132 and the compressed higher pressureworking fluid flows out from the discharge port 133B of the compressor132.

The compressor 132 is a multispeed compressor. In other embodiments, thecompressor 132 may be a single speed compressor. The compressor 132 canbe driven by a prime mover (not shown). For example, the prime mover maybe an internal combustion engine, an electrical drive motor, or acombination thereof. In some embodiments, the CCU 100 can include acombination of an internal combustion engine and an electric drive motorand can be configured to use the internal combustion engine alone or theelectric drive motor alone. In some embodiments, the CCU 100 can includea combination of an internal combustion engine and an electric drivemotor and can be configured to use a combination thereof (e.g., bothoperating at the about the same time to power the various components ofthe CCU 100, etc.). In some embodiments, the CCU 100 may be anelectrically powered system that relies upon one or more batteries thatare recharged using a local power source (e.g., an internal combustionengine of the CCU 100, an internal combustion engine of a tractor, etc.)and/or utility power.

The condenser 134 cools the compressed working fluid as it passesthrough the condenser 134. As indicated by the dotted arrows in FIG. 2 ,ambient air passes through the condenser unit 120 via its ambient airinlet 122 and its ambient air outlet 124. The ambient air flows throughthe condenser 134 as it flows through the condenser unit 120. Thecondenser 134 is a heat exchanger that allows the working fluid and theambient air to be in a heat transfer relationship without physicallymixing as they each flow through the condenser 134. As the working fluidflows through the condenser 134, the ambient air absorbs heat from theworking fluid and cools the working fluid. The working fluid is cooledby the condenser 134 and becomes liquid or mostly liquid as it passesthrough the condenser 134. In some embodiments, ambient air may not beused to directly cool the working fluid. For example, the ambient airmay be used to cool an intermediate heat transfer fluid (e.g., asolution including water, glycol, etc.), and the cooled intermediateheat transfer fluid passes through the condenser 134 to the cool theworking fluid.

The working fluid flows from the condenser 134 to the EEIV 140. As shownin FIG. 2 , the liquid working fluid in this embodiment flows from thecondenser 134 to the EEIV 140 by passing through the receiver tank 152and an economizer 154. The condenser 134 and the receiver tank 152located in the condenser unit 120, while the EEIV 140 and the economizer154 are located in the evaporator unit 110. The working fluid passingfrom the condenser unit 120 to the evaporator unit 110 as it flows fromthe condenser 134 to the EEIV 140.

The EEIV 140 expands the cooled working fluid from the condenser 134.The EEIV 140 allows the working fluid to expand as it flows through theEEIV 140. The expansion causes the working fluid to decrease intemperature. For example, the expansion by the EEIV 140 drops thepressure of the working fluid by at or about 90% or greater than 90%.The expanded working fluid is in a two-phase gaseous/liquid phase. Theexpanded gaseous/liquid working fluid flows from the EEIV 140 to theevaporator 150 via the distributor 156. The distributor 156 distributesthe expanded working fluid into the evaporator 150.

The EEIV 140 includes a valve housing 142 and a stepper motor 144. TheEEIV 140 is configured to be opened to various degrees (e.g., fullyopen, 75% open, 50% open, 25% open, etc.) and to be closed (e.g., has aclosed position configured to entirely block the flow of working fluidthrough the EEIV 140). The EEIV 140 is adjustable to different degreesof open to change the flow rate of the working fluid through the EEIV140. As discussed herein, it should be understood that “closed” means avalve is fully closed, and that “open” means the valve is in valveposition other than fully closed (e.g., a fully open valve position, a75% open valve position, in a 50% open valve position, in a 25% openvalve position, etc.). The EEIV 140 is operated (e.g., adjusted to aspecific valve positon) using the stepper motor 144. The stepper motor144 controls the valve position of the EEIV 140. In an embodiment, thestepper motor 144 is coupled to a valve body 146 of the EEIV 140 andmoves the valve body 146 relative to an orifice 148 of the EEIV 140. Forexample, the EEIV 140 is closed by the stepper motor 144 moving thevalve body 146 to a closed position that seals the orifice 148.

During normal operation (e.g., when providing conditioning and noleakage of working fluid leak is detected), the climate controller 180controls the stepper motor 144 to adjust the flowrate through the EEIV140. The number of steps for the stepper motor 144 may vary based on theconfiguration of climate controlled transport unit in a particularembodiment (e.g., the configuration of the CCU 100, the climate controlcircuit 130, and/or the climate controlled space 102). The stepper motor144 can have a number of steps that allows the stepper motor 144 toquickly close the EEIV 140 while still allowing precise control of theflow through EEIV 140 for precise control of the conditioning of theclimate controlled space 102. The stepper motor 144 may be configured tohave, for example, 800 steps. For example, the first step (e.g., stepone) and the last step (e.g., step 800) can correspond to the EEIV 140being closed and being fully open (e.g., 100% open), or vice-versa. Inan embodiment, the stepper motor 144 can have a different number ofsteps than 800. The stepper motor 144 is also configured to beadjustable to each of its steps that are between its first step and itslast step. The stepper motor 144 can allow the EEIV 140 to respondfaster (e.g., close faster, open faster, etc.) than previous electronicexpansion valves. The EEIV 140 also includes a step position sensor 182for the stepper motor 144. The step position sensor 182 can be used todetect the current step position SP of the stepper motor 144 (e.g., thecurrent step of the stepper motor 144). The step positon SP of thestepper motor 144 can correspond with the valve position of the EEIV 140as the movement of the stepper motor 144 changes the valve position ofthe EEIV 140. The climate controller 180 is configured to detect, viathe step position sensor 182, the step position SP of the stepper motor144. In an embodiment, the climate controller 180 uses the step positionSP of the stepper motor 144 to detect the current valve position of theEEIV 140 (e.g., the degree that the EEIV 140 is open, if the EEIV 140 isclosed), as the step position SP corresponds with the valve position ofthe EEIV 140. Operation of the EEIV 140 is discussed in more detailbelow.

An “electronic” expansion valve is an expansion valve that is driven byan electronic motor to adjust the degree that the valve is open (e.g.,to vary the amount of working fluid flowing through the expansionvalve). In contrast, a “mechanical” expansion valve is driven by amechanical fluid system in which variation in the superheat of theworking fluid automatically adjusts the degree that the valve is open(e.g., a temperature sensing bulb in which variation in working fluidtemperature automatically adjusts the degree that the valve is open). An“isolation” valve is a valve configured to seal closed to block fluidtherethrough (e.g., a closed position in which the valve's office issealed shut). For example, the EEIV 140 is both i) an “electronicexpansion” valve as the EEIV 140 is configured to be adjustable by itselectronic stepper motor 144 and ii) an “isolation” valve as the EEIV140 is configured to have a closed position in which the EEIV 140 issealed closed (e.g., the closed position in which its valve body 146seals the orifice 148, the EEIV 140 is 100% closed).

The evaporator 150 heats the working fluid as it passes through theevaporator 150. As shown in FIG. 2 , the air to be conditioned (e.g.,air from the climate controlled space 102) flows through the evaporatorunit 110 physically separate from the working fluid via the evaporatorair inlet 112 and the evaporator air outlet 114. The air passes throughthe evaporator 150 as it flows through the evaporator unit 110. Theevaporator 150 is a heat exchanger that allows the working fluid and theair to be in a heat transfer relationship without physically mixing asthey each flow through the evaporator 150. As the working fluid flowsthrough the evaporator 150, the working fluid absorbs heat from the airand cools the air. The working fluid is heated by the evaporator 150 andbecomes gaseous or mostly gaseous as it passes through the evaporator150.

The heated working fluid flows from the evaporator 150 back to thecompressor 132. As shown in FIG. 2 , the gaseous/mostly gaseous workingfluid in this embodiment flows from the evaporator 150 to the compressor132 by passing through the economizer 154, an electronic check valve160, and the accumulator tank 158. The evaporator 150 and the economizer154 are located while the evaporator unit 110, while the compressor 132and the accumulator tank 158 are located within the condenser unit 120.The working fluid passing from the evaporator unit 110 to the condenserunit 120 as it flows from the evaporator 150 to the compressor 132.

The compressor 132 receives lower pressure working fluid and dischargeshigher pressure compressed working fluid, while the EEIV 140 receiveshigher pressure working fluid and discharges expanded lower pressureworking fluid. Accordingly, the climate control circuit 130 includes ahigh-pressure side 170 and a low-pressure side 172. The high-pressureside 170 is a portion of the climate control circuit 130 that extendsfrom the discharge port 133B of the compressor 132 to the EEIV 140 andincludes the condenser 134. The high-pressure side 170 receives thehigher pressure compressed working fluid discharged by the compressor132 and supplies it to the EEIV 140. The low-pressure side 172 is aportion of the climate control circuit 130 that extends from the EEIV140 to the suction port 133A of the compressor 132 and includes theevaporator 150. The low-pressure side 172 receives lower pressureexpanded working fluid from the EEIV 140 and supplies it to thecompressor 132.

As shown in FIG. 2 , the climate control circuit 130 also includes anelectronic check valve 160 that is downstream of the evaporator 150 andupstream of the compressor 132. The working fluid passes through theelectronic check valve 160 as it flows from the evaporator 150 to thecompressor 132. The valve of the electronic check valve 160 is aconventional check valve that only allows the working fluid to flowthrough in a forward direction. The working fluid attempting to flowthrough the check valve in the reverse direction automatically moves itsvalve body into a closed position that seals the check valve andprevents working fluid from flowing through. The electronic check valve160 automatically opens/closes based on fluid flow and is not driven bya motor, solenoid, etc. The electronic check valve 160 can preventworking fluid in the condenser unit 120 from flowing into the evaporatorunit 110.

In FIG. 2 , the electronic check valve 160 is located in the condenserunit 120. In other embodiments, the climate control circuit 130 mayinclude the electronic check valve 160 in a different location after theevaporator 150 and before the compressor 132 than shown in FIG. 2 . Theelectronic check valve 160 may be located in the evaporator unit 110. Inan embodiment, the electronic check valve 160 may be located in theevaporator unit 110 downstream of the evaporator 150 and the economizer154 and upstream of the compressor 132 (e.g., the location A in FIG. 2). In an embodiment, the electronic check valve 160 may be located inthe evaporator unit 110 downstream of the evaporator 150 and upstream ofthe economizer 154 and the compressor 132 (e.g., the location B in FIG.2 ).

The electronic check valve 160 includes a proximity sensor 162. Theproximity sensor 162 is used to detect a valve position of theelectronic check valve 160 (e.g., whether the electronic check valve 160is open or closed). The proximity sensor 162 is attached to the outsideof the electronic check valve 162 (e.g., attached to the outside of avalve housing of the electronic check valve 160) or into the housing ofthe electronic check valve 162 without extending into the interior ofthe electronic check valve 162 (e.g., does not pass through the housinginto passageway for the working fluid, does not require openings orholes that extend through the valve housing of the electronic checkvalve 160, etc.). The proximity sensor 162 avoids adding anyopenings/holes into the electronic check valve 160 that are potentialleakage paths for the working fluid. In an embodiment, the proximitysensor 162 is a magnetic field sensor attached to the outside of theelectronic check valve 160. The proximity sensor 162 measures a magneticfield of the electronic check valve 160, which is different between theopen position and the closed position of the electronic check valve 160(e.g., the closed position results in a first magnetic field and theclosed position results in second magnetic that is different from thefirst magnetic field). For example, the positon of the gate (not shown)within the electronic check valve 160 affects the magnetic fieldmeasured by the proximity sensor 162. The climate controller 180 can beconfigured to detect, via the proximity sensor 162, whether theelectronic check valve 160 is open or closed.

During normal operation, the climate controller 180 is configured tocontrol the EEIV 140 so that the working fluid heated by the evaporator150 (e.g., the working fluid after the evaporator 150 and before thecompressor 132) has a desired amount of superheat. The superheat of afluid is the difference between its current temperature and its dewpoint at its current pressure (e.g.,T(P_(x))superheat=T(P_(x))Current−T(P_(x))Saturation temperature). Thedesired amount of the superheat can vary based on the configuration of aparticular CCU and/or a climate control circuit. For example, thepredetermined amount of superheat can be selected to minimize superheatwhile ensuring the working fluid retains sufficient superheat whenentering the compressor 132 (e.g., enough superheat to preventsignificant condensation of the refrigerant in working fluid before orwithin the compressor 132). Generally, the efficiency of the CCU 100decreases as the amount of superheat is increased while significantcondensation of the refrigerant can damage the compressor 132.

The saturation temperature of the working fluid at operating pressure(s)of the climate control circuit 130 can be known from, for example,previous testing of the working fluid and/or its components (e.g.,testing of its refrigerant(s), etc.). Therefore, the predeterminedamount of superheat can correspond to a (predetermined) targettemperature/temperature range for the heated working fluid (e.g.,T(P_(x))Target=Tsuperheat+T(P_(x))Saturation Temperature). For example,the target temperature or temperature range, the predetermined amount ofsuperheat, and/or the saturation temperature(s) for the working fluidcan be stored in the memory of the climate controller 180. The climatecontrol 180 is configured to operate the climate control circuit 180 sothat the working fluid after being heated by the evaporator 150 is atthe target temperature or within the target temperature range.

In an embodiment, the pressures in the climate control circuit 130 varybased on its operation (e.g., the discharge pressure of a multispeedcompressor can vary with its speed, etc.). To maintain the predeterminedamount of superheat, the target temperature/temperature range can bedetermined based on a detected evaporator outlet pressure of the workingfluid (e.g., the current pressure of the heated working fluid). Theclimate controller 180 can be configured to detect the pressure of theheated working fluid directly (e.g., with a pressure sensor) orindirectly (e.g., based on current speed of the compressor 132, based oncurrent electrical power being provided to an electric motor for thecompressor 132, based on a discharge pressure of the compressor 132,etc.). For example, the climate control circuit 130 can include apressure sensor 188 that measures a pressure P₁ of the working fluidafter passing through evaporator 150. The pressure sensor 188 is locateddownstream of the evaporator 150 and upstream of the compressor 132. Asshow in FIG. 2 , the pressure sensor 188 is located at or near the inletof the compressor 132 and measures a pressure P₁ at the suction inlet ofthe compressor 132. The pressure sensor 188 can also be referred to as asuction pressure sensor. In an embodiment, the pressure sensor 188 maybe located closer to the outlet of the evaporator 150. For example, thepressure sensor 188 can be located at the outlet of the evaporator 150or between the evaporator 150 and the economizer 154 in the climatecontrol circuit 130.

The climate controller 180 can be configured to detect one or more ofthe evaporator inlet temperature, the evaporator outlet temperature(e.g., heated working fluid temperature T₁), compressor dischargepressure (e.g., compressed working fluid pressure P₁), evaporatorpressure (e.g., heated working fluid pressure/suction pressure P₁), andthe step position SP of the stepper motor 144. In an embodiment, theclimate controller 180 can be configured to detect for leaking workingfluid, an overcharge of the climate control circuit 130, and/or anundercharge of the climate controller circuit 130 based on one or moreof these detected parameters of the climate control circuit 130.

As shown in FIG. 2 , the climate control circuit 130 includes atemperature sensor 184 located after the evaporator 150 and before thecompressor 132. The temperature sensor 184 can be used to detect atemperature T₁ of the working fluid after being heated by the evaporator150. For example, the temperature sensor 184 can be configured to detectthe temperature T₁ of the working fluid discharged from the evaporator150. The climate controller 180 can detect the temperature T₁ of theheated working fluid using the temperature sensor 184. The climatecontroller 180 is configured to control the EEIV 140 so that thetemperature T₁ of the heated working fluid is at the target temperature(or temperature range). As discussed above, the target temperature ortemperature range can vary with the pressure of the heated workingfluid. In an embodiment, the climate control circuit 130 is configuredto detect a pressure of the heated working fluid indirectly (e.g., basedon electrical current supplied to the compressor 132, discharge pressureof the compressor 132, etc.) or directly (e.g., via a pressure sensor).

A climate control circuit is configured to utilize a specific amount ofworking fluid (e.g., has a designed working fluid capacity). Thecapacity of a climate control circuit varies based on its particularconfiguration (e.g., the sizing of the components in the climate controlcircuit, etc.). An operator and/or technician may fill a climate controlcircuit with more working fluid than its designed capacity, which can bereferred to as overcharging. An operator and/or technician may fill aclimate control circuit with less working fluid than its designedcapacity, which can be referred to as undercharging. As shown in FIG. 2, the EEIV 140 can include a temperature sensor 186. The temperaturesensor 186 is on the high-pressure side 172 of the EEIV 140 (e.g.,located before the orifice 148, etc.). The temperature sensor 186measures a temperature T₂ of the unexpanded compressed working fluid inthe EEIV 140. The temperature T₂ of the unexpanded working fluid is thetemperature of the compressed working fluid after being discharged fromthe compressor 132 (e.g., after the discharge port 133B, etc.) andbefore being expanded by the EEIV 140 (e.g., before the orifice 148,etc.). For example, the temperature sensor 186 measures a temperature T₂of the unexpanded working fluid within the EEIV 140. The climatecontroller 180 can detect the temperature T₂ of the unexpanded workingfluid via the temperature sensor 186.

As shown in FIG. 2 , the climate control circuit 130 can include adischarge pressure sensor 189 for measuring the pressure P₂ of theunexpanded working fluid. The discharge pressure 189 measures thepressure P₂ of the compressed working fluid in the high-pressure side172 of the climate control circuit 130. The pressure P₂ of theunexpanded working fluid is the pressure of the compressed working fluidafter being compressed by the compressor 132 and before being expandedby the EEIV 140. For example, the pressure sensor 189 is provideddownstream of the compressor 132 and upstream of the EEIV 140 in theclimate control circuit 130. The climate controller 180 can detect thepressure P₂ of the unexpanded working fluid via the pressure sensor 189.

In an embodiment, the climate controller 180 is configured to detectovercharging of the climate control circuit 130 based on subcooling ofthe compressed working fluid. Subcooling is the difference between thesaturation temperature (“T_(SAT)”) and the actual temperature T₂ of theunexpanded working fluid (e.g., subcooling=T_(SAT)−T₂). As discussedabove, the saturation temperature of a fluid is based on its pressure(e.g., T_(SAT) is determined based on the detected pressure P₂). Theclimate controller 180 can determine the subcooling of the unexpandedworking fluid based on the pressure P₂ and the temperature T₂ of theunexpanded working fluid. The climate controller 180 determines that theclimate control circuit 130 is overcharged when the subcooling isgreater than a predetermined threshold. In an embodiment, the subcoolingis detected for the compressed working fluid after being compressed bythe compressor and before being expanded by the EEIV.

In an embodiment, the climate controller 180 is configured to detectundercharging of the climate control circuit 130 based on operation ofthe EEIV 140. For example, the climate controller 180 may determine thatthe climate control circuit 130 is undercharged based on comparing anexpected step position of the EEIV 140 to an actual step positon SP. Anundercharge may be detected when the variance between the expected steppositon and the actual step position for the EEIV 140 is greater than apredetermined threshold. For example, the climate controller 180 maydetermine that the climate control circuit 130 is undercharged based oncomparing the temperature of the working fluid heated by the evaporatorto an expected temperature of said working fluid. An undercharge may bedetected when the variance between the expected temperature of and theactual temperature of the heated working fluid is greater than apredetermined threshold. Such comparisons are discussed in more detailbelow. In such embodiments, the climate controller 180 may determinethat the climate control circuit 130 is undercharged (instead ofleaking) based on whether a trend in the variance exceeds apredetermined limit.

As discussed above, leaking of the working fluid is potentiallydangerous due to the flammability of its refrigerant. In particular,leaking of the refrigerant into the climate controlled space can bedangerous as it can cause the climate controlled space to become aflammable environment (e.g., an environment in which an ignition sourcecauses flame propagation/an explosion). An ignition source (e.g., spark,flame, etc.) does not cause a propagating flame/explosion until arefrigerant concentration reaches its reaches a minimum concentration,which is known as a lower flammability limit.

The climate controller 180 is configured to isolate the high-pressureside 170 of the climate control circuit when the leaking of workingfluid is detected. When working fluid is leaking from the climatecontrol circuit 130, the climate controller 180 is configured to atleast shutdown the compressor 132 and close the EEIV 140. The EEIV 140is closed by the stepper motor 144 adjusting the EEIV 140 to its closedposition. The compressor 132 when shutdown is configured to blockworking fluid from flowing through the compressor 132 (e.g., configuredso that working fluid cannot flow through the shutdown compressor 132).The isolation is configured to block the working fluid in thehigh-pressure 170 side from flowing to the low-pressure side 172 by atleast the closed EEIV 140 and the shutdown compressor 132. The isolationprevents the working fluid from flowing from the high-pressure side 170to the low-pressure side 130 of the climate controller circuit 130. Forexample, if a leak occurs in the evaporator 150, the isolation limitsthe amount of refrigerant/working fluid that can leak through theevaporator 150 by preventing the working fluid in the high pressure side170 from flowing to the evaporator 150. The isolation of the climatecontrol circuit 130 helps limit the potential leakage of working fluidinto the condenser unit 120, and therefore limits the amount of workingfluid that can leak into the climate controlled space 102 and cause itto become a flammable environment.

In some embodiments, the climate control circuit 130 may have additionalfluid connection(s) that fluidly connect the high-pressure side 170 andthe low pressure side 170 (e.g., a hot gas bypass, etc.). In such anembodiment, isolating the high-pressure side 170 can include the climatecontroller 180 operating additional component(s) of the climate controlcircuit 130 (e.g., valves, etc.) in the additional fluid connection(s)to block each additional fluid connection. In an embodiment, the climatecontroller 180 can be configured to maintain the isolation of thehigh-pressure side (e.g., preventing a startup of the shutdowncompressor 132, keeping the EEIV 140 closed, etc.) until receivinginstructions that the leakage is repaired. An operator and/or technicianmay instruct the climate controller 180 that the leak is repaired via,for example, a HMI 190 and/or a telematics unit 192 connected to theclimate controller 180.

In an embodiment, the climate controller 180 can also be configured todetect a location of a leak in the climate control circuit 130. Afterisolating the high-pressure side 170, the climate controller 180 detectsa valve position of the electronic check valve 160 using the proximitysensor 162. If the electronic check valve 160 is open, the leak can bedetermined to be in the low-pressure side 172 of the climate circuit 130downstream of the electronic check valve 160. For such a leak, the openelectronic check valve 160 can allow working fluid in the low-pressureside 172 upstream of the electronic check valve 160 (e.g., working fluidwithin the evaporator 150, etc.) to flow and leak into the internalvolume 126 of the condenser unit 120, where it can escape to and besafely dissipated into the external environment 104. If the electroniccheck valve 160 is closed, the leak can be either in the high-pressureside 170 of the climate control circuit 130 or between the EEIV 140 andthe electronic check valve 160 (e.g., in the evaporator 150). For such aleak, the closed electronic check valve 160 prevents working fluid thatis between the electronic check valve 160 and the compressor 132 (e.g.,working fluid in the accumulator tank 158) from flowing and leaking intothe condenser unit 120, where the leaked working fluid will flow intothe climate controlled space 102.

As shown in FIG. 2 , the climate controller 180 can be connected to theHMI 190 and the telematics unit 192. The HMI 190 allows the climatecontroller 130 to display a warning to an operator of the climatecontrolled transport unit (e.g., climate controlled transport unit 1) ofthe CCU 100. In an embodiment, the CCU 100 includes the HMI 190. In anembodiment, a vehicle for moving transport unit of the TCCS (e.g., thetractor 5 in FIG. 1 , etc.) includes the HMI 190. The telematics unit192 allows the climate controller 130 to wirelessly communicate awarning to a remote device (not shown) (e.g., a computer, a server, aserver network, etc.). In an embodiment, the TCCS may include thetelematics unit 192. In an embodiment, a vehicle for moving transportunit of the TCCS (e.g., tractor 5 in FIG. 1 , etc.) includes thetelematics unit 192.

FIG. 3 is a schematic diagram of a CCU 200, according to anotherembodiment. The CCU 200 can be utilized in a transport climate controlsystem (e.g., the transport climate control system 10 in FIG. 1 , etc.)to condition a climate controlled space 202. The CCU 200 includes aclimate control circuit 230 that can be utilized to control anenvironmental condition (e.g., temperature, humidity, air quality, etc.)of the climate controlled space 202. In an embodiment, the climatecontrolled space 202 is the climate controlled space of a transport unit(e.g., climate controlled space 12 of transport unit 10 in FIG. 1 ,etc.).

The CCU 200 in FIG. 3 has a similar configuration to the CCU 100 in FIG.2 , except for an isolation valve 260 being provided between theevaporator 250 and the compressor 232 instead of an electronic checkvalve. For example, the CCU 200 includes an evaporator unit 210, acondenser unit 220, and a climate control circuit 230 controlled by aclimate controller 280. For example, the CCU 200 includes the compressor232, a condenser 234, an EEIV 240 with a stepper motor 244, theevaporator 250, a receiver tank 252, an economizer 254, a distributor256, and an accumulator tank 258. The climate controller 280 may also beconnected to an HMI 290 and a telematics unit 292 similar to the climatecontroller 180. It will be appreciated that the CCU 200 in FIG. 3 inother embodiments may be modified in a similar manner as discussed abovewith respect to the CCU 100 in FIG. 2 .

A working fluid flows through the climate controlled circuit 230 and isused to condition air supplied to the climate controlled space 202. Inan embodiment, the working fluid includes flammable refrigerant assimilarly discussed above for the working fluid of the climate controlcircuit 130 in FIG. 2 . As similarly discussed above regarding the CCU100 in FIG. 2 , the climate controller 280 is configured to isolate thehigh-pressure side 270 of the climate control circuit 230 when itdetects that working fluid is leaking.

As shown in FIG. 3 , the climate control circuit includes the isolationvalve 260 that is disposed downstream of the evaporator 250 and upstreamof compressor 232 in the climate control circuit 230. The working fluidpasses through the isolation valve 260 as it flows from the evaporator250 to the compressor 232. In FIG. 3 , the isolation valve 260 isprovided in the condenser unit 220. In other embodiments, the climatecontrol circuit 260 may include the isolation valve 260 in a differentlocation downstream of the evaporator 250 and upstream of the compressor232 than shown in FIG. 3 . The isolation valve 260 may be located in theevaporator unit 210. In an embodiment, the isolation valve 260 may belocated in the evaporator unit 210 downstream of the evaporator 250 andthe economizer 256 and upstream the compressor 232 (e.g., location A₂ inFIG. 3 , etc.). In an embodiment, the isolation valve 260 may be locatedin the evaporator unit 210 downstream of the evaporator 250 and upstreamof the economizer 252 and the compressor 232 (e.g., location B₂ in FIG.3 , etc.).

The climate controller 280 controls the isolation valve 260. Theisolation valve 260 has an open position and a closed position. In theclosed position, the working fluid is blocked from flowing through theisolation valve 160. In an embodiment, the isolation valve 260 has anon/off configuration with two valve positions of fully open and closed.In contrast to a check valve that opens/closes automatically by thepressure of the working fluid, an isolation valve is activated by anexternal force. For example, the isolation valve 260 is activated bysupplying air, hydraulics, electrical current, etc. to the isolationvalve 260. The isolation valve 260 switches positions when activated(e.g., moves from its closed position to its open position, moves fromits closed position to its open position). The isolation valve 260 canhave a fail-close configuration in which the isolation valve 260 revertsto its closed position when not being activated. In an embodiment, theisolation valve 260 is a solenoid valve. For example, the climatecontroller 280 may supply electrical current to the isolation valve 260to activate it.

In an embodiment, the isolation valve 260 includes a feedback sensor262. The feedback sensor 262 is connected to the climate controller 260and provides a confirmation regarding the operation of the isolationvalve 260. The confirmation can be an electrical signal. The feedbacksensor 262 is configured to send a confirmation that the isolation valve260 is in its closed position. For example, the climate controller 130switches the isolation valve 260 to its closed position when a leak isdetected. Once the isolation valve 260 moves to its closed position, thefeedback sensor 262 sends the confirmation to the climate controller280. The feedback sensor 262 ensures that the isolation valve 260 closescorrectly to block flow of working fluid.

The climate controller 280 is configured to isolate a portion 272A ofthe low-pressure side 272 of the climate circuit 230 when the workingfluid is leaking. The portion 272A of the climate circuit 230 extendsfrom the EEIV 240 to the isolation valve 260. The portion 272A of theclimate control circuit 230 includes the evaporator 250. When workingfluid leakage is detected, the climate controller 280 is configured toisolate the high-pressure side 270 and also close the isolation valve260, which isolates the portion 272A of the low-pressure side 272 of theclimate control circuit 230. For example, the closed EEIV 240 and theclosed isolation valve 260 isolate the portion 272A of the low-pressureside 272 of the climate control circuit 230.

When a working fluid leak is detected, the climate controller 280 isconfigured to isolate the climate circuit 230 into at least threedifferent sections: the high-pressure side 270, the first portion 272Aof the low-pressure side 272, and a second portion 272B of thelow-pressure side 272. The working fluid is prevented from flowingbetween the isolated sections. When a leak occurs in the climate controlcircuit 230, the isolation prevents working fluid in other sections fromflowing into the section with the leak. For example, if a leak occurs inthe first portion 272A of the low-pressure side 272 (e.g., in theevaporator 250, etc.), the isolation prevents the working fluid withinthe high-pressure side 270 and the working fluid within the secondportion 272B of the low-pressure side 272 from flowing into the firstportion 272 and through the leak into the evaporator unit 210 and theninto the climate controlled space 202. The isolation of the climatecontrol circuit 230 helps limit the potential leakage of working fluidinto the condenser unit 210, and therefore limits the amount of workingfluid that can leak into the climate controlled space 202 and cause itto become a flammable environment. The second portion 272B extends fromthe isolation valve 262 to the compressor 232. As shown in FIG. 3 , thesecond portion 272B can include the accumulator tank 258.

FIG. 4 is a flow chart for a method 1000 of controlling a TCCS thatincludes a climate control circuit. In an embodiment, the method 1000may be employed by the TCCS 20 in FIG. 1 and as described above. In anembodiment, the method 1000 may be employed by the climate controller180 in FIG. 2 to control a TCCS including the CCU 100 in FIG. 2 and asdescribed above. The method 1000 starts at 1010.

At 1010, the TCCS operates a climate control circuit (e.g., climatecontrol circuit 130) to condition a climate controlled space (e.g.,climate controlled space 12, climate controlled space 102). In anembodiment, the climate controlled space is the climate controlled spaceof a transport unit (e.g., climate controlled space 12 of transport unit10 in FIG. 1 ). The climate control circuit includes a compressor (e.g.,compressor 132), a condenser (e.g., condenser 134), an EEIV (e.g., EEIV140), and an evaporator (e.g., evaporator 150). The compressorcompresses the working fluid, the condenser cools the working fluid, theEEIV expands the working fluid, and the evaporator heats the workingfluid. For example, the climate controlled circuit operates in a coolingmode to supply conditioned air (e.g., cooled air, etc.) to the climatecontrolled space. The method 1000 then proceeds to 1020.

At 1020, the climate controller of the TCCS (e.g., climate controller180) detects whether working fluid is leaking from the climate controlcircuit. In an embodiment, the climate controller 1020 may detect thatthe working fluid is leaking based on one or more monitored parametersof the climate controlled transport unit (e.g., climate controlledtransport unit 1). The climate controller 1020 may utilize one or moresensors (e.g., temperature sensor, pressure sensor, air quality sensor,etc.) to monitor said parameter(s).

In some embodiments, detecting whether the working fluid is leaking 1020can include comparing actual operation of an EEIV to an expectedoperation of the EEIV based on one or more step position(s) of the EEIV.The EEIV can include a stepper motor (e.g., stepper motor 144) thatadjusts the valve positon of the EEIV and a stepper position sensor(e.g., step position sensor 182). The climate controller can beconfigured to detect, via the step position sensor, the step position ofthe stepper motor.

As discussed above, the climate controller can be configured to adjustthe EEIV based on a superheat of the working fluid (e.g., to adjust theEEIV so that the temperature T₁ is at a target temperature/range, etc.).For example, leaking refrigerant results in the climate circuit having alesser amount of working fluid. The lessor amount of working fluid inthe climate control circuit can result in the EEIV having to be openlarger to allow more working fluid therethrough and maintain the sameamount of cooling by the evaporator. Specific relationship(s) betweenthe other operating parameters and the step position of the EEIV in theclimate control circuit with no leaks can be determined based onprevious testing (e.g., of the climate control circuit, of a climatecontrol circuit with the same or similar configuration, etc.). Theclimate controller can use these relationship(s) based on the stepposition(s) of the EEIV to detect if the working fluid is leaking.

In an embodiment, detecting whether the working fluid is leaking 1020can include the climate controller comparing the step position of theEEIV to an expected step position 1022. Comparing a step position to anexpected step position 1022 can include the climate controller detectingoperating conditions of climate control circuit, and comparing the stepposition(s) of the EEIV to expected step position(s) based on theoperating conditions of the climate control circuit. For example, theclimate controller is configured to detect step position(s) of EEIV(e.g., one or more step positions of the stepper motor of the EEIV) andtemperature(s) of the working fluid (e.g., temperature T₁ of the heatedworking fluid, temperature T₁ of the working fluid over time, etc.) andpressure(s) of the working fluid (e.g., pressure P₁ of the workingfluid, a discharge pressure of the compressor, pressure P₁ or dischargepressure of the compressor over time, etc.). In some embodiments, one ormore of the operation conditions may have been detected in the operatingof the climate control circuit at 1010.

An expected step position can be the step position expected based on thetemperature of the working fluid and the pressure of the working fluidused for determining the superheat of the working fluid (e.g.,temperature T₁, pressure P₁, an operation parameter for indirectlydetecting the pressure, etc.). The climate controller can be configuredto determine that the working fluid is leaking when the variance betweenthe actual step position of the EEIV (e.g., a detected step position)and the expected step position exceeds a predetermined threshold (e.g.,a predetermined step amount, a predetermined numbers of steps, etc.). Inan embodiment, the climate controller may be configured to determinethat the working fluid is leaking at 1022 when a trend of said varianceexceeds a predetermined limit (e.g., change in the variance isincreasing by greater than X steps per minute, etc.). For example, theclimate controller is configured to periodically determine the variancebetween the actual step position of the EEIV and an expected stepposition, and then determines a trend in the variance over apredetermined period (e.g., trend of the variance determinations overthe previous X minutes/hours, etc.). The climate controller can thendetermine that working fluid is leaking at 1022 when the trend of thevariance in the step position of the EEIV exceeds the predeterminedlimit. This can also be referred to as drift. In some embodiments, thetrend in variance can be useful for determining whether the heattransfer circuit is undercharged or is leaking.

In an embodiment, detecting whether the working fluid is leaking 1020can include comparing the temperature of the working fluid heated by theevaporator to an expected temperature of said working fluid 1024.Comparing the temperature of heated working fluid to the expectedtemperature of the heated working fluid at 1024 can include detectingoperating conditions of climate control circuit. For example, theclimate controller is configured to detect a first step position of theEEIV, a second step positon of EEIV (e.g., the step position of thestepper motor of the EEIV), a first temperature of the heated workingfluid (e.g., temperature T₁ of the heated working fluid at the firststep positon), and a second temperature of the heated working fluid(e.g., temperature T₁ of the heated working fluid at the second steppositon).

When the climate controller adjusts the EEIV to control the temperatureof the heated working fluid (e.g., to control superheat, to controltemperature T₁, etc.), the climate controller is configured to comparehow the adjustment of the EEIV affects the temperature of the heatedworking fluid to how it would be expected to affect the saidtemperature. For example, the climate controller can determine that theadjustment of the EEIV (e.g., from a detected first step position to adetected second step position, etc.) can be expected to increase ordecrease the heated working fluid by X degrees (e.g., increase ordecrease its superheat by X degrees, increase or decrease thetemperature T₁ by X degrees). This temperature change is the expectedtemperature of the heated working fluid.

In an embodiment, the climate controller at 1024 can be configured todetermine that a leak has occurred based on variance between the actualtemperature of the working fluid (e.g., detected temperature T₁) and theexpected temperature of the working fluid. For example, when thevariance is greater than a predetermined threshold (e.g., apredetermined temperature amount). In an embodiment, the climatecontroller may be configured to determine that the working fluid isleaking at 1024 when a trend of said variance exceeds a predeterminedlimit (e.g., change in the variance is increasing by greater than Xdegrees per minute, etc.). For example, the climate controller isconfigured to periodically determine the variance between the actualstep position of the EEIV and an expected step position, and thendetermines a trend in the variance over a predetermined period (e.g.,trend of the variance determinations over the previous X minutes/hours,etc.). The climate controller can then determine that working fluid isleaking at 1024 when the trend of the variance in the step position ofthe EEIV exceeds the predetermined limit. In some embodiments, the trendin variance can be useful for determining whether the heat transfercircuit is undercharged or is leaking. In some embodiments, the climatecontroller is configured to use an average of the variation or a timeaverage of the detected temperature(s), pressure(s), etc.

In an embodiment, detecting whether the working fluid is leaking at 1020may utilize different types of working fluid/refrigerant leak detection.For example, the climate controller may utilize a refrigerant detector(not shown) to detect if there is refrigerant in the climate controlledspace and/or the internal space of the CCU (e.g., the internal space ofthe condenser unit, the internal space of the evaporator unit, etc.).The method 1000 then proceeds to 1030. At 1030, when leaking of theworking fluid from the climate control circuit is detected, the method1000 proceeds to 1040. When leaking of the working fluid from theclimate control circuit is detected, the method 1000 returns to 1010.For example, the climate controller at 1010 continues the climatecontrol circuit's conditioning of the climate controlled space when noworking fluid leakage is detected.

At 1040, the climate controller isolates the high-pressure side of theclimate control circuit (e.g., high-pressure side 170, high-pressureside 270) when its detected that the working fluid is leaking. Isolatingthe high-pressure side can include shutting down the compressor at 1042and closing the EEIV at 1044. For example, the isolation of thehigh-pressure side at 1040 can prevent the working fluid in thehigh-pressure side from flowing into the low-pressure side of theclimate control circuit (e.g., low-pressure side 172, etc.). In anembodiment, the shutdown of the compressor at 1042 can occur prior tothe closing of the EEIV at 1044 (e.g., prior to the EEIV reaching itsclosed position). The method 1000 then proceeds to 1050. The method 1000then proceeds to optional 1050.

At 1050, the climate controller determines a location of a leak in theclimate control circuit. The climate control circuit can include anelectronic check valve (e.g., electronic check valve 160) with aproximity sensor (e.g., proximity sensor 162). In an embodiment,determining a location of a leak in the climate control circuit 1050 caninclude detecting, via the proximity sensor 162, the valve position ofthe electronic check valve 1052. The valve position of the electroniccheck valve (e.g., open or closed) can indicate the location of the leakin the climate control circuit as discussed above with respectelectronic check valve 160 in the FIG. 2 . The method the proceeds tooptional 1060.

At 1060, the climate controller issues a warning that there is a workingfluid leak. The warning may include the location of a leak as determinedat 1050. In an embodiment, issuing the warning 1060 can include an HMI(e.g., HMI 190) connected to the climate controller displaying thewarning to warn an operator of the climate controlled transport unit(e.g., climate controlled transport unit 1). In an embodiment, issuingthe warning 1060 can include a telematics unit (e.g., telematics unit192) connected to the climate controller wirelessly sending the warningto a remote device (e.g., a computer, a server, a server network, etc.).

In some embodiments, the method 1000 can include the climate controllermaintaining the isolation at 1040 until receiving instructions that theleakage is repaired. For example, the climate controller can beconfigured to prevent a startup of the compressor until instructed thatthe leak is repaired. An operator and/or technician may instruct theclimate controller that the leak is repaired via, for example, a HMI(e.g., HMI 190) and/or a telematics unit (e.g., telematics unit 192)connected to the TCCS. In such embodiments, the method 1000 would stayat 1040, 1050, or 1060 until receiving said instructions. Afterreceiving instructions that the leakage has been repaired, method 1000can proceed back to 1010 from 1040, 1050, or 1060. For example, theclimate controller can be configured to resume climate conditioning(e.g., startup the compressor, open the EEIV) once it receivesinstructions that the leak has been repaired.

FIG. 5 is a flow chart for a method 1100 of controlling a transportclimate control system (TCCS) that includes a climate control circuit,according to another embodiment. In an embodiment, the method 1110 maybe employed by the TCCS 20 in FIG. 1 and as described above. In anembodiment, the method 1100 may be employed by the climate controller280 in FIG. 2 to control a TCCS that includes the CCU 200 in FIG. 3 andas described above. The method 1100 starts at 1110.

The method 1100 is similar to the method 1000 in FIG. 4 , except for1150. For example, the method 1100 includes operating a climatecontrolled space to condition a climate controlled space at 1110,determining whether the working fluid is leaking from the climatecontrol circuit at 1120, returning to 1110 or proceeding to 1140 basedon whether the working fluid is leaking, isolating a high-pressure sideof the climate control circuit at 1140, and sending a warning at 1160,similar to the method 1000 in FIG. 4 . After isolating a high-pressureside of the climate control at 1140, the method 1100 can proceed from1140 to optional 1150.

At 1150, the climate controller (e.g., climate controller 280) isolatesa portion of the low-pressure side (e.g., portion 272A of low-pressureside 272) of the climate control circuit (e.g., climate control circuit230). Isolating the portion of the low-pressure side of the climatecontrol circuit 1150 can include closing an isolation valve 1152 (e.g.,isolation valve 260) in the climate control circuit. The isolation valveis located in the low-pressure side of the climate control circuit. Forexample, the isolation valve is located downstream of the evaporator(e.g., evaporator 250) and upstream of the compressor (e.g., compressor232) in the climate control circuit. In FIG. 5 , isolating the portionof the low-pressure side 1150 occurs after closing the EEIV 1142 in1140. In an embodiment, isolating the portion of the low-pressure side1150 may occur before or simultaneously with the closing of the EEIV1142 and after the shutdown of the compressor 1142. The method 1100 thenproceeds to optional 1160.

At 1160, the climate controller issues a warning that there is a workingfluid leak. In an embodiment, issuing the warning 1160 includes an HMI(e.g., HMI 290) connected to the climate controller displaying thewarning for warning an operator of the climate controlled transport unit(e.g., climate controlled transport unit 1). In an embodiment, issuingthe warning 1160 includes a telematics unit (e.g., telematics unit 292)connected to the climate control wirelessly transmitting the warning toa remote device (e.g., a computer, a server, a server network, etc.).

In some embodiments, the method 1100 can include the climate controllermaintaining the isolation at 1140 and 1150 until receiving instructionsthat the leakage is repaired. For example, the climate controller can beconfigured to prevent a startup of the compressor until instructed thatthe leak is repaired. An operator and/or technician may instruct theclimate controller that the leak is repaired via, for example, a HMI(e.g., HMI 190) and/or a telematics unit (e.g., telematics unit 192)connected to the TCCS. In such embodiments, the method 1100 would stayat 1150 or 1160 until receiving said instructions. After receivinginstructions that the leakage has been repaired, method 1100 can proceedback to 1110 from 1150 or 1160. For example, the climate controller canbe configured to resume climate conditioning (e.g., startup thecompressor, open the EEIV, open the isolation valve, etc.) once itreceives instructions that the leak has been repaired.

FIG. 6 is a flow chart for a method 1200 of controlling a transportclimate control system (TCCS) that includes a climate control circuit,according to yet another embodiment. In an embodiment, the method 1200may be employed by the TCCS 20 in FIG. 1 and as described above. In anembodiment, the method 1200 may be employed to control a TCCS thatincludes the CCU 100 in FIG. 2 and as described above or to control aTCCS that includes the CCU 200 in FIG. 3 and as described above. Themethod 1200 starts at 1210.

At 1210, a climate control circuit (e.g., climate control circuit 130,climate control circuit 230) is operated to condition a climatecontrolled space (e.g., climate controlled space 12, climate controlledspace 102, climate controlled space 202). In an embodiment, the climatecontrolled space is the climate controlled space of a transport unit(e.g., climate controlled space 12 of transport unit 10 in FIG. 1 ,etc.). The climate control circuit includes a compressor (e.g.,compressor 132, the compressor 232), a condenser (e.g., condenser 134,condenser 234), an EEIV (e.g., EEIV 140, EEIV 240), and an evaporator(e.g., evaporator 150, evaporator 250). The compressor compresses theworking fluid, the condenser cools the working fluid, the EEIV expandsthe working fluid, and the evaporator heats the working fluid. Forexample, the climate controlled circuit operates in a cooling mode tosupply conditioned air (e.g., cooled air) to the climate controlledspace. The method 1200 then proceeds to 1270 and optionally proceeds tooptional 1220.

The method 1200 includes detecting whether working fluid is leaking fromthe climate control circuit at 1220, which proceeds to determiningwhether the working fluid is leaking at 1230, which proceeds toreturning back to 1210 or to isolating a high-pressure side of theclimate control circuit at 1240. 1220, 1230, and 1240 in FIG. 6 aresimilar to 1020, 1030, and 1040 described in FIG. 4 . In an embodiment,1220, 1230, and 1240 in the method 1200 have features similar to 1020,1030, and 1040 of the method 1000, respectively, as described above.

In an embodiment, the method 1200 may include determining a location ofa leak in the climate control leak at 1050 and/or sending a warning at1060 similar to the method 1050 of the method 1000 as shown in FIG. 4and as described above. In an embodiment, the method 1200 may includeisolating a portion of the low-pressure side of the climate controlcircuit at 1150 and/or sending a warning at 1160 of the method 1100 asshown in FIG. 5 and as described above. In some embodiments, the method1200 can include the climate controller maintaining the isolation at1240 until receiving instructions that the leakage as similarlydiscussed above for the method 1000 or as similarly discussed above forthe method 1100.

At 1270, the climate control controller monitors for an overcharge or anundercharge of the climate control circuit. Monitoring for an overchargeor undercharge of the climate control circuit can include performing1272, 1276, 1278, 1280 and 1282. At 1272, the climate controller detectsone or more operating parameters of the climate control circuit.Detecting the one or more parameters 1272 can include detecting a valveposition of the EEIV 1274, detecting the temperature (e.g., temperatureT₁, etc.) of the working fluid heated by the evaporator 1275, and/ordetecting a temperature (e.g., temperature T₂, etc.) and pressure (e.g.,pressure P₂, etc.) of the unexpanded working fluid 1276.

Detecting the valve position of the EEIV at 1274 can include the climatecontroller detecting, via a step position sensor (e.g., step positionsensor 182), a step position of the stepper motor (e.g., stepper motor144, stepper motor 244) of the EEIV. Detecting the temperature of theworking fluid heated by the evaporator at 1275 can include the climatecontroller detecting, via a temperature sensor (e.g., temperature sensor184), the temperature of the working fluid after being heated by theevaporator.

Detecting the temperature of the unexpanded working fluid at 1276 caninclude the climate controller detecting, via a temperature sensor(e.g., temperature sensor 186), the temperature of the unexpandedworking fluid. In an embodiment, climate controller detects thetemperature of the unexpanded working fluid within the EEIV.

Detecting the pressure of the unexpanded working fluid at 1276 caninclude the climate controller detecting, via a pressure sensor (e.g.,pressure sensor 189), the pressure of the unexpanded working fluid. Inan embodiment, detecting the temperature of the unexpanded working fluidmay include the climate controller indirectly detecting the pressure ofthe unexpanded working fluid (e.g., based on current speed of thecompressor, based on current electrical power being provided to anelectric motor for the compressor, etc.). The method 1200 then proceedsto 1278.

At 1278, the climate controller determines a subcooling of the workingfluid and/or expected operation of the EEIV. The subcooling at 1278 isthe subcooling of the unexpanded working fluid (e.g., the compressedworking fluid prior to being expanded by the EEIV) as similarlydiscussed above. The subcooling of the unexpanded working fluid can beused to determining if the climate control circuit is overcharged. Forexample, subcooling is the difference between the saturation temperature(“T_(SAT)”) and the actual temperature T₂ of the unexpanded workingfluid (e.g., subcooling=T_(SAT)−T₂). The climate controller 180 candetermine the subcooling of the unexpanded working fluid based on thepressure P₂ and the temperature T₂ of the unexpanded working fluid. Themethod 1200 then proceeds to 1280.

In an embodiment, determining the expected operation of the EEIV at 1278can include determining an expected step position of the EEIV. Forexample, the climate controller can determine the expected step positionin a similar manner as discussed above for the method 1000. In anotherembodiment, determining the expected operation of the EEIV at 1278 caninclude an expected temperature of the working fluid after being heatedby the evaporator. For example, the climate controller can determine theexpected temperature of the heated working fluid in a similar manner asdiscussed above for the method 1000

At 1280A, the determined subcooling is compared to a predeterminedthreshold. The climate controller 180 can determine that the climatecontrol circuit 130 is overcharged when the subcooling is greater than apredetermined threshold. When the subcooling does not exceed thepredetermined threshold (e.g., the subcooling is equal to or less thanthe threshold), the method 1200 proceeds to 1280B. When the subcoolingexceeds the predetermined threshold, the method 1200 proceeds to 1282.

At 1280B, the expected operation of the EEIV is compared to the actualoperation of the EEIV. In an embodiment, the climate controller cancompare the expected step position of the EEIV to the actual stepposition of the EEIV (e.g., step position POS). In another embodiment,the climate controller can compare the expected temperature of theworking fluid heated by the evaporator to the detected temperature ofthe working fluid heated by the evaporator (e.g., temperature T₁). Whenthe difference between the expected operation of the EEIV and the actualoperation of the EEIV does not exceed a predetermined threshold (e.g.,temperature amount, step amount, etc.), the method 1200 returns to 1210.When the difference between the expected operation of the EEIV and theactual operation of the EEIV does exceed the predetermined threshold,the method 1200 proceeds to 1282. At 1282, the climate controller issuesa warning that the climate control circuit is overcharged orovercharged. In an embodiment, issuing the warning at 1280 includes aHMI (e.g., HMI 190, HMI 290) connected to the climate controllerdisplaying the warning to an operator of the climate controlledtransport unit (e.g., climate controlled transport unit 1). In anembodiment, issuing the warning 1280 includes a telematics unit (e.g.,telematics unit 192, telematics unit 292) connected to the climatecontroller wirelessly communicating the warming to a remote device(e.g., a computer, a server, a server network, etc.).

The method 1200 in FIG. 6 has 1280A and 1280B as being subsequent steps.However, 1280A and 1280B may occur in a different order. In anembodiment, the order of 1280A and 1280B may be switched in the method1200. In another embodiment, 1280A and 1280B may occur in parallel inthe method 1200. FIG. 6 shows the method 1200 including both detectingfor overcharge and undercharge of the climate control circuit. However,the method 1200 in some embodiments may include just one of detectingfor an overcharge or detecting for an undercharge of the climate controlcircuit. In such an embodiment, the method 1200 can include just one of1280A or 1280B.

In some embodiments, detecting for an overcharge or undercharge of theclimate control circuit at 1270 may be combined with detecting whetherworking fluid is leaking fluid from the climate control circuit at 1220.For example, detecting whether the working fluid is leaking from theclimate control circuit at 1220 can include detecting a valve positionof the EEIV (e.g., for comparing the step position of the EEIV to anexpected step position at 1022 in the method 1000, for comparing thetemperature of the working fluid heated by the evaporator to an expectedtemperature of said working fluid at 1024 in the method 1000). Theclimate controller can be configured to detect a valve position of theEEIV, and the detected valve positon may be used in both detectingwhether working fluid is leaking from the climate control circuit at1220 (e.g., for comparing the step position to, for comparingtemperature of the heated working fluid, etc.) and in detecting forovercharging of the climate control circuit at 1270 (e.g., indetermining a subcooling of the EEIV at 1278). In an embodiment, theclimate controller may be configured to shutdown the climate controlcircuit (e.g., shutdown the compressor, etc.) when it determines thatthere is an overcharge of the climate control circuit at 1280B. Forexample, method 1200 may include shutting down the climate controlcircuit between 1280B and 1282, or after sending the warning at 1282.

Aspects

Any of aspects 1-10 can be combined with any of aspects 11-20, and anyof aspects 11-13 can be combined with aspects 14-20.

Aspect 1. A method of controlling a transport climate control system(TCCS) for a transport unit, the TCCS including a climate controlcircuit with a compressor and an electronic expansion and isolationvalve (EEIV), the method comprising:

operating the climate control circuit to condition a climate controlledspace of the transport unit, wherein operating the climate controlcircuit to condition the climate controlled space includes compressing aworking fluid with the compressor and expanding the working fluid withthe EEIV;

detecting for leaking of the working fluid from the climate controlcircuit; and

isolating a high-pressure side of the climate control circuit whendetected that the working fluid is leaking from the climate controlcircuit.

Aspect 2. The method of aspect 1, wherein the high-pressure side of theclimate control circuit is isolated from the low-pressure side of theclimate control circuit.

Aspect 3. The method of either one of aspects 1 or 2, wherein isolatingthe high-pressure side of the climate control circuit includes closingthe EEIV and shutting down the compressor.

Aspect 4. The method of any one of aspects 1-3, further comprising:

isolating a portion of a low-pressure side of the climate controlcircuit when detected that the working fluid is leaking from the climatecontrol circuit.

Aspect 5. The method of aspect 4, wherein the climate control circuitincludes an evaporator to heat the working fluid, the portion of thelow-pressure side extending through an evaporator unit containing theevaporator.

Aspect 6. The method of either one aspects 4 or 5, wherein isolating theportion of the low-pressure side of the climate control circuit includesclosing an isolation valve downstream of the evaporator and upstream ofthe compressor in the climate control circuit.Aspect 7. The method of any one of aspect 1-6, wherein

expanding the working fluid in the EEIV includes a stepper motoradjusting the EEIV based on a superheat of the working fluid, and

detecting for leaking of the working fluid from the climate controlcircuit includes:

detecting at least one step position of the EEIV and one or more otheroperational parameters of the climate control circuit, and

comparing operation of the EEIV to an expected operation of the EEIV,the expected operation of the EEIV being operation of the EEIV expectedfrom the detected at least one step position of the EEIV and thedetected one or more other operational parameters of the climate controlcircuit.

Aspect 8. The method of any one of aspects 1-7, further comprising:

detecting for overcharge of the climate control circuit, whereindetecting for the overcharge of the climate control circuit includes:

-   -   detecting a temperature and a pressure of the working fluid        compressed by compressor,    -   determining a subcooling of the working fluid compressed by the        compressor based on the temperature and the pressure of the        working fluid compressed by the compressor, and    -   detecting that the climate controlled circuit is overcharged        when the subcooling is greater than a predetermined threshold.        Aspect 9. The method of aspect 8, wherein the EEIV includes a        temperature sensor positioned on a low-pressure side of the        EEIV, the detected temperature of the working fluid expanded by        the EEIV being detected via the temperature sensor of the EEIV.        Aspect 10. The method of any one of aspects 1-3 and 7-9, further        comprising:

determining a location of a leak in the climate control circuit whendetected that the working fluid is leaking from the climate controlcircuit, wherein determining a location of the leak in the climatecontrol circuit includes:

-   -   detecting a valve position of an electronic check valve, the        electronic check valve being downstream of the evaporator and        upstream of the compressor in the climate control circuit, and    -   determining a location of the leak in the climate control        circuit based on the detected valve position of the electronic        check valve.        Aspect 11. A method of controlling a transport climate control        system (TCCS) for a transport unit, the TCCS including a climate        control circuit with a compressor to compress a working fluid        and an electronic expansion and isolation valve (EEIV) to expand        the working fluid, the method comprising:

operating the climate control circuit to condition a climate controlledspace;

detecting for at least one of overcharge and undercharge of the climatecontrol circuit, wherein detecting for overcharge of the climatecontrolled circuit includes:

-   -   detecting a temperature and a pressure of the compressed working        fluid, and    -   determining a subcooling of the compressed working fluid based        on the temperature and the pressure of the compressed working        fluid,

wherein detecting for an undercharge includes:

-   -   detecting a step position of the EEIV, and    -   determining an expected operation of the EEIV based on a step        position of the EEIV; and

sending a warning when determined that the climate controlled circuit isat least one of overcharged or undercharged.

Aspect 12. The method of aspect 11, wherein the EEIV includes atemperature sensor, and the detected temperature of the working fluidafter being compressed by the EEIV being detected via the temperaturesensor of the EEIV.

Aspect 13. A transport climate control system (TCCS) for a transportunit, comprising:

a climate control circuit including:

-   -   a compressor to compress a working fluid,    -   a condenser to cool the working fluid compressed by the        compressor,    -   an electronic expansion and isolation valve (EEIV) to expand the        working fluid condensed by the condenser, and    -   an evaporator to heat the working fluid expanded by the EEIV;        and

a climate controller configured to:

-   -   detect for the working fluid leaking from the climate control        circuit, and    -   isolate a high-pressure side of the climate control circuit when        determined that the working fluid is leaking from the climate        control circuit.        Aspect 14. The TCCS of aspect 13, wherein the climate controller        is configured to close the EEIV and shutdown the compressor, in        order to isolate the high-pressure side of the climate control        circuit.        Aspect 15. The TCCS of any one of aspects 13 and 14, wherein the        EEIV includes a stepper motor and a step position sensor for        detecting a step position of the stepper motor, and

the climate controller is configured to:

-   -   detect, via the step position sensor, at least one step position        of the stepper motor,    -   detect one or more other operational parameters of the climate        control circuit, and    -   comparing operation of the EEIV to an expected operation of the        EEIV, the expected operation of the EEIV being operation of the        EEIV expected from the detected at least one step position and        the detected one or more other operational parameters of the        climate control circuit.        Aspect 16. The TCCS of any one of aspects 13-15, wherein

the climate controller is configured to:

-   -   detect a valve position of the EEIV and a temperature of the        working fluid expanded by the EEIV,    -   determine an expected temperature of the working fluid expanded        by the EEIV based on the detected valve position of the EEIV,    -   determine a subcooling of the EEIV by comparing the expected        temperature of the working fluid expanded by the EEIV to the        detected temperature of the working fluid expanded by the EEIV,    -   determine that the climate control circuit is overcharged when        the subcooling is greater than a predetermined threshold.        Aspect 17. The TCCS of any one of aspects 13-16, wherein

the climate control circuit includes an isolation valve downstream ofthe evaporator and upstream of the compressor, and

the climate controller is configured to isolate a portion of alow-pressure side of the compressor by closing the isolation valve whendetected that the working fluid is leaking from the climate controlcircuit.

Aspect 18. The TCCS of aspect 17, further comprising:

a climate control unit including an evaporator unit and a condenserunit, the evaporator unit including the evaporator, and the condenserunit including the condenser, wherein

the portion of the low-pressure side extends through the evaporatorunit.

Aspect 19. The TTCS of any one of aspects 13-16, wherein

the climate control circuit includes an electronic check valve with aproximity sensor, and

the climate controller configured to:

-   -   detect, via the proximity sensor, a valve position of the        electronic check valve, and    -   determine a location of a leak in the climate control circuit        based on the detected valve position of the electronic check        valve.

The examples disclosed in this application are to be considered in allrespects as illustrative and not limitative. The scope of the inventionis indicated by the appended claims rather than by the foregoingdescription; and all changes which come within the meaning and range ofthis application.

What is claimed is:
 1. A method of controlling a transport climatecontrol system (TCCS) for a transport unit, the TCCS including a climatecontrol circuit with a compressor, an evaporator, and an electronicexpansion and isolation valve (EEIV), the method comprising: operatingthe climate control circuit to condition a climate controlled space ofthe transport unit, wherein operating the climate control circuit tocondition the climate controlled space includes compressing a workingfluid with the compressor and expanding the working fluid with the EEIV;detecting for leaking of the working fluid from the climate controlcircuit; and isolating a high-pressure side of the climate controlcircuit when it is detected that the working fluid is leaking from theclimate control circuit, wherein detecting for leaking of the workingfluid from the climate control circuit includes determining a locationof a leak in the climate control circuit, wherein determining a locationof the leak in the climate control circuit includes: detecting a valveposition of an electronic check valve, the electronic check valve beingdownstream of the evaporator and upstream of the compressor in theclimate control circuit, and determining a location of the leak in theclimate control circuit based on the valve position of the electroniccheck valve.
 2. The method of claim 1, wherein the high-pressure side ofthe climate control circuit is isolated from a low-pressure side of theclimate control circuit.
 3. The method of claim 1, wherein isolating thehigh-pressure side of the climate control circuit includes closing theEEIV and shutting down the compressor.
 4. The method of claim 1, furthercomprising: isolating a portion of a low-pressure side of the climatecontrol circuit when it is detected that the working fluid is leakingfrom the climate control circuit.
 5. The method of claim 4, wherein theevaporator is configured to heat the working fluid, the portion of thelow-pressure side extending through an evaporator unit containing theevaporator.
 6. The method of claim 4, wherein isolating the portion ofthe low-pressure side of the climate control circuit includes closing anisolation valve downstream of the evaporator and upstream of thecompressor in the climate control circuit.
 7. The method of claim 1,wherein expanding the working fluid in the EEIV includes a stepper motoradjusting the EEIV based on a superheat of the working fluid, anddetecting for leaking of the working fluid from the climate controlcircuit includes: detecting at least one step position of the EEIV andone or more other operational parameters of the climate control circuit,and comparing operation of the EEIV to an expected operation of theEEIV, the expected operation of the EEIV being operation of the EEIVexpected from the detected at least one step position of the EEIV andthe detected one or more other operational parameters of the climatecontrol circuit.
 8. The method of claim 1, further comprising: detectingfor overcharge of the climate control circuit, wherein detecting for theovercharge of the climate control circuit includes: detecting a pressureand a temperature of the working fluid compressed by compressor,determining a subcooling of the working fluid compressed by thecompressor based on the temperature and the pressure of the workingfluid compressed by the compressor, and detecting that the climatecontrolled circuit is overcharged when the subcooling is greater than apredetermined threshold.
 9. A transport climate control system (TCCS)for a transport unit, comprising: a climate control circuit including: acompressor to compress a working fluid, a condenser to cool the workingfluid compressed by the compressor, an electronic expansion andisolation valve (EEIV) to expand the working fluid condensed by thecondenser, and an evaporator to heat the working fluid expanded by theEEIV; and a climate controller configured to: detect for the workingfluid leaking from the climate control circuit, and isolate ahigh-pressure side of the climate control circuit when the controllerdetects that the working fluid is leaking from the climate controlcircuit, wherein the climate control circuit includes an electroniccheck valve with a proximity sensor, and the climate controller isconfigured to: detect, via the proximity sensor, a valve position of theelectronic check valve, and determine a location of a leak in theclimate control circuit based on the valve position of the electroniccheck valve.
 10. The TCCS of claim 9, wherein the climate controller isconfigured to close the EEIV and shutdown the compressor, in order toisolate the high-pressure side of the climate control circuit.
 11. TheTCCS of claim 9, wherein the EEIV includes a stepper motor and a stepposition sensor for detecting a step position of the stepper motor, andthe climate controller is configured to: detect, via the step positionsensor, at least one step position of the stepper motor, detect one ormore other operational parameters of the climate control circuit, andcomparing operation of the EEIV to an expected operation of the EEIV,the expected operation of the EEIV being operation of the EEIV expectedfrom the detected at least one step position and the detected one ormore other operational parameters of the climate control circuit, inorder to detect that the working fluid is leaking from the climatecontrol circuit.
 12. The TCCS of claim 9, wherein the climate controlleris configured to: detect a valve position of the EEIV and a temperatureof the working fluid expanded by the EEIV, determine an expectedtemperature of the working fluid expanded by the EEIV based on the valveposition of the EEIV, determine a subcooling of the EEIV by comparingthe expected temperature of the working fluid expanded by the EEIV tothe detected temperature of the working fluid expanded by the EEIV, anddetermine that the climate control circuit is overcharged when thesubcooling is greater than a predetermined threshold.
 13. The TCCS ofclaim 9, wherein the climate control circuit includes an isolation valvedownstream of the evaporator and upstream of the compressor, and theclimate controller is configured to isolate a portion of a low-pressureside of the compressor by closing the isolation valve when it isdetected that the working fluid is leaking from the climate controlcircuit.
 14. The TCCS of claim 13, further comprising: a climate controlunit including an evaporator unit and a condenser unit, the evaporatorunit including the evaporator, and the condenser unit including thecondenser, wherein the portion of the low-pressure side extends throughthe evaporator unit.